ITP (In Cell Touch Panel) integrates the touch function to the liquid crystal displays, and detecting the varying intensity of light from panel surface while touching which is achieve to touch sensing. It provides numerous advantages such as low cost, thin bodies and more convenient use.
Please refer to FIG. 1. The signals transported between metal 3 layer 7′ and the metal 2 layer 4′ in existing ITP product, which is according to four holes on insulating layer1 6′ and insulating layer2 8′ by etching on touch panel switch. Metal 3 layer 7′ bridge over two holes etched on insulating Layer2 8′, metal 2 layer 4′ bridge over two holes simultaneously etched on both insulating layer1 6′ and insulating Layer2 8′. The metal 3 layer 7′ and the metal 2 layer 4′ communicate to each other by bottom Indium Tin Oxide layer 9′ which coated on inner surface of four holes and upper surface of insulating Layer2 8′. However, as shown in FIG. 2. When the back value is 0.6 um, the metal 3 layer 7′ is bridge over to four holes so that bottom Indium Tin Oxide 9′ cannot connect to metal 2 layer 4′. It will cause metal 3 layer 7′ cannot communicate to metal 2 layer 4′. Therefore metal 3 layer 7′ needs to increase back value to 0.9 um (shown as FIG. 1) for ensure the design within process capability, it will restrict both design and process windows.